A marble processing plant (MPP) can achieve sustainable development by implementing energy-saving and consumption-reduction technology. Reducing energy loss in such an energy-intensive plant is crucial for overall energy savings. This study establishes an MPP optimization model based on the second law of thermodynamics and the law of conservation of mass. Marble is an aesthetically pleasing and long-lasting building material that has boosted economies in European and sub-Saharan African nations. However, high energy costs and scarcity have constrained the industry’s economic potential and hindered the achievement of optimal levels of production. The second law of thermodynamics is adopted to study the irreversibilities, inefficiencies, and exergetic performance of a marble processing plant. The Aspen Plus commercial software application is used to model and generate thermodynamic data, determine energy flow streams and conduct sensitivity and optimization analysis to improve data quality and energetic performance outcomes. From the results, the various scales of the exergetic destruction, efficiencies, and exergetic losses are determined, and recommendations are established. The overall energy and exergy efficiency levels were determined to be 87.43% and 86.84%, respectively, with a total exergetic destruction of 200.61 kW. The reported methodologies, cutting-edge ideas, and solutions will give industrialists and other significant stakeholders in the global manufacturing sector cutting-edge information about energy usage and ways to cut energy losses in both new and existing factory designs, manage energy cost components, and adjust energy efficiency to maximize productivity.